To make the pancakes put the flour, baking powder and espresso powder in a bowl and stir together. In a different bowl, whisk together the eggs, melted butter and milk. Gradually stir the wet mix into the dry to make a batter. Leave to sit while you make everything else.
To make the mocha syrup, put the sugar, cocoa powder and espresso powder in a pan with 100ml water and heat, whisking, until glossy and sugar has melted. Stir in the vanilla.
Mix the mascarpone with the icing sugar, Kahlúa and vanilla.
Heat a non-stick pan and brush it with butter. Pour enough batter into the pan to make a thick American-style pancake (about 10cm diameter). Wait for about a minute until the surface starts to form bubbles and has set, then flip the pancake over and cook until golden.
Remove to a plate, then brush the pan with more butter and repeat with the rest of the pancake batter (you might need to adjust the heat as you cook the pancakes).
To serve, make a pancake tower (putting a dollop of mascarpone between each one) and drizzle with the mocha syrup. Add a few chocolate covered coffee beans to decorate.